In Madame de Mauves James uses for the first time his theme of international relationships. Euphemia Cleve is a young American woman who is beautiful, good, and virtuous. She is married to a French Baron, Richard de Mauves, who is anything but good and virtuous.
The story is mainly told through the eyes of a third person, a wealthy American named Longmore. Longmore meets Euphemia through a mutual acquaintance, Mrs. Draper. Mrs. Draper entrusts Longmore with the task of bringing some happiness to Euphemia as she writes to him, Prove to Madame de Mauves that an American friend may mingle admiration and respect better than a French husband.